Variable speed driving mechanism



P 1936- w. B. BRONANDER 2,054,802

VARIABLE SPEED-DRIVING MECHANISM Filed April 17, 1955 as I Z0 2/ A B ll l4 /3 g f 45 M .39 i Y 25 Patented Sept. 22, 1936 v UNITED STATES PATENT" OFFICE This invention relates to variable speed driving mechanisms. This invention has for its salient object to provide a method and mechanism wherebya difi'er-,

3 ential transmission may be operated by a plurality of driving units and the units may be controlled as to speed, rotation and direction of rotation in such a mannerv that the driven element may be driven at an infinite number of speeds in 10 either direction, or may be driven at zero speed or be held stationary.

Another object of the invention is to provide a differential power transmission with apair of (driving units connected to different parts of the 18 differential mechanism in'such a way that when the units are rotating in opposite directions at the same speed no resultant drive will be ob-. tained, when one unit is rotating faster than the other a reduced speed-will be obtained, controlled so by the rotation of the faster unit, and when bothv units are rotating in the same direction at the same speed a direct drive will be obtained.

Another object of the'invention is to so couple a pair of internal combustion engines to adif- 25 ferential driving mechanism and to so regulate the operation of the engines. as to direction and speed that the drive will be transmitted at a plurality of speeds in-either direction,

Further objects of the invention will appear 30 from the following specification taken in connection withthe drawing which forms a part of this application, and in which Fig.- 1 is an elevational view illustrating a differential drive constructed in accordance with 85 the invention, parts of the mechanism being shown insection; and

Fig. 2 -is an elevational view similar to Fig. l but illustrating another common form of planetary differential mechanism and also showing the 40 driving units as of different sizes.

The invention briefly described consists of differential mechanism including a spider having planetgearsmounted thereon and operatively connected tola driven shaft and a pair of gears 4 meshing with said planet gears, each of said pair of gears being independently driven by a separate power unit, such as an internal combustion engine. Means is provided for controlling the operation of each power .unit in such a way as to 50 regulate the speed of operation of the unit or to prevent the operation of the unit. When one unit or engine is operating in a direction opposite to the direction of rotation of the other unit and the two units are operating at the same speed, no

55 power will be-transmitted through thediiferential mechanism or through the spider to the driven element. When the .two units are driven in thb' same direction at the same speed a direct drive will be obtained. When one unit is rotating at a different speed than the other unit, the. 5 unit rotating at the higher speed will control the drive. 1

Further details of the invention will appear from the following description.

In the embodiment of the invention illustrated in Fig. 1 there is shown a diiferential gearing comprising planet gears HI, ID carried by a spider ll having a gear l2 formed or mounted thereon which meshes with a gear l3 mounted on the, driven shaft M which, as shown, may drive the wheels l5, I5 of a railroad truck. A pair of gears 20, 2| mesh with the planet gears Ill, Ill. "The gear is mounted on a shaft 22 of an engine unit A which is preferably an internal combustion engine, a Diesel type engine 20 being shown. A fly wheel .23 is mounted on the shaft 22. The speed of the engine A is controlled by a .valve carried by a valve stem or rod 24 which controls the fuel fed through a conduit 25 to 'a fuel 25 pump P, the fuel being discharged or fed by the pump through a conduit 26 to the engine cylinder 21. A governor G is mounted on the engine A and is constructed in any suitable manner to operate a lever 30 which is mounted on a fixed pivot 3| 30 and engages the outer end of the valve stem 24. A spring 32 retracts the valve. The fuel feed may be manually controlled by means of a lever 33 mounted o a fixed pivot 34 and operating through the end .of the lever 30 to push in the 35 valve stem 24 and thus control the fuel supply. The engine exhaust conduit is shown at 35 and a valve 36 is mounted therein and is manually controlled to regulate the opening through the exhaust conduit. When the valve 36 is in the posi- 40 tion shown, a back pressure will be built up in the engine and when this pressure has reached a predetermined amount further rotation of the engine will be prevented. The engine B is connected to the gear 2| and is operated and controlled in the same manner and by the same mechanism as that above described. w

The driving mechanism illustrated in Fig. 1 opcrates as follows: Both engines A and Bare Started up in the usual way, but one of these engines normally rotates in one direction and'the other in the opposite direction. The governors G control the speed 01' the engine and when the two engines are operating in op posite directions at the same speed the spider will not be rotated and no drive will be effected. In order to propel the vehicle or drive the driven shaft one of the engines will be slowed down, thus causing one of the'gears 20, 2| to be rotated slower than the other gear. This differential in the speed of rotation oi the two gears will cause the spider to rotate, thus transmitting the drive to the gear I! and shaft l4. The direction of drive will be controlled by the direction of rotation of the faster of the vehicle or the speedcaused by the momentum of the rolling parts. This will cause the en gine B tobe turned over and started in the same direction of rotation as the engine A. Engine B will then be brought up to the speed of engine A and the spider l l and gear I! carried thereby will rotate at the same speed and in the same direction as the speed of rotation and direction of rotation of the engine shafts.

In order to reverse the drive the engine which is controlling the forward drive will be slowed down and stopped and the direction of rotation of the other engine will cause the drive to be reversed.

The construction shown in Fig. 2 is similar to that shown in Fig. 1 except that engine B is smaller than engine A and in this embodiment of the invention the spider 4| carries a gear 42 a. which meshes with a gear 43 on a stub shaft 44.

This shaft also carries a gear 45 which meshes with a gear 46 on a shaft 41 to which is secured a propeller 48.

The shaft 52 of engine A has secured thereto a ring gear 53 which engages planet gears 54 carried by the spider 4|. The shaft 55 of the engine.

B is connected through a clutch 56 which may be manually controlled in any suitable manner to a shaft 51 on which is mounted a pinion Bl which also meshes with the planet gears 54. A fly wheel is formed on or secured to the spider 4 I. The clutch I8 is provided so that the smaller engine B may be used to start the larger engine A or, in other words, as starting motor. The two engines A and are controlled in the same manner as those illustrated in Fig. 1. In this form of the inventionthe engine A will be normallyrotated in a direction to give'a forward drive to the shaft 41. k v

The arrangement shown in Fig. 2 is operated in the same manner as that shown in Fig. 1 and can accomplish the same resultant drives.

From the foregoing specification it will be seen that/the rotation of the driven shaft is controlled by the regulation and control of the driving units A and B and that by controlling these units in the manner above described an infinite number.

of speeds can be obtained and that the drive can be easily and quickly changed from neutralor'no drive to any desired forward or reverse speed. It will be understood that, although internal combustion engines are illustrated and are preferred in carrying out this method and driving control, that other power units could be utilized and would accomplish the same results.

Although certain specific embodiments of the invention have been particularly shown and described, it will be understood that the invention is capable of modification andthat changes in the construction and in the arrangement. of the various cooperating parts may be made without departing from the spirit or scope of the invention, as expressed in the following claims.

What I claim is: I 1. Driving mechanism comprising a planet gear spider, planet gears mounted thereon, a driven shaft operatively connected to said spider, a pair of gears meshing with said planet gears,

aneinternal combustion, Diesel type engine connected to drive each of said pair of gears, means for controlling the speed of each engine, and means for controlling the exhaust of each engine in a manner to substantially close the exhaust conduit and build up back pressure to slow down or stop the engine whereby the driving engine will reverse the drive of the other engine and cause both engines to drive in the same direction.

2. The method of driving a driven shaft and parts connected thereto through difierential gearing, including planet gears carried by a spider and a pair of gears meshing therewith which consists of separately and independently driving each gear of said pair of gears by an internal combustion engine, operating said engines in opposite directions at difierent speeds, from zero speed tomaximum speed, to obtain a drive below the speed of the driving engine, and changing from said drive to direct drive by driving one engine while the other is substantially stationary, then reducing momentarily the speed of the driven engine so that the rotation of the driven parts, due to momentum, will rotate and start the stationary engine and rotate both engines in the direction of rotation of the operating engine. v

8. The method of driving a driven shaft and parts connected theretoto obtain infinitely variable speeds in either direction through differential gearing, including planet gears carried by a spider and a pair of gears meshing therewith, which consists of separately and independently driving each gear of said pair of gears by an internal combustion engine, using one of said engines as a drag to retard the rotation of the gear connected thereto while driving the gearing by the other engine, to obtain a drive at a speed'below the speed of the driving engine and obtaining direct drive by reversing the direction of rotation of the drag engine by momentarily reducing the speed of the driving engine and utilizing the momentum of the driven parts to start the drag engine and drive both engines in the same direction. I

4. The method of reversing one of two differentially interconnected engines which consists ofwhich consists of utilizing the kinetic energy 7 gine and utilizing the momentum oi the driven generated by driving one engine against the re-- sistance oi the other engine to force both engines to drive in the same direction. I

'i. The method of driving a driven shai through difierential mechanism, including a pair of difierentiahelements and a third difierentiai element operatively connected to said pair of elements, which consists of separately-and independently driving each of said pair of diiflerential elements by an internal combustion engine, using one of said engines as a drag to retard the rotation of the difierential element connected thereto while driving the difierentiai mechanism by the other engine, to obtain a drive at a speed below the speed of the driving engine and obtaining direct drive by reversing the direction oi rotation of the drag engine by momentarily reducing the speed of the driving enparts to start the drag engine and drive both engines in the same direction.

8. In combination, a pair of internal combustion, Diesel engines, a shaft driven by each engine, each engine having a fuel intake and an exhaust, iuel control means for each engine' means to close the exhaust of each engine, said differential mechanism including three difierential elements, one of said elements being operatively connected to-each of said engine shafts, a driven shaft connected to the third difierential element whereby either engine may be slowed down and used as a drag by closing the exhaust thereof and the direction of rotation of said drag engine can be reversed by utilizing the momentum of the driven parts.

WH HEHi/Z B. BRONANDER. 

